Legionnaries Disease

What is legionella and Legionnaires’ disease?

Legionella are bacteria that can thrive in warm water between 20C and 40C that has remained at that temperature for a period of time. It is spread in fine water spray from showers or taps. It is however, unlikely to occur in a normal residential environment.

Whose responsibility is it to ensure that the risk from exposure to legionella is properly controlled?

The responsibility test as defined by the HSE is as follows:-

If a boiler, tap or shower head breaks/leaks in the property it is the person who is responsible for getting it repaired.

Note: The responsibility cannot be delegated to a third party by any kind of agreement.

What is the landlord’s responsibility?

The HSE provide guidance in an Approved Code of Practice (ACOP). This advice is not a legal requirement or compulsory and landlords will not be in breach of any statutory requirement or fined for not complying. However, in the event of a tenant contracting legionnaires disease the landlord will be expected to show that the risks had been assessed and if necessary, measures taken to reduce the risks taken.

HSE Approved Code of Practice

The HSE publish an Approved Code of Practice and guidance in regulations. The latest version may be purchased from the HSE. Version L8 (Fourth Edition) Published in 2013 may be downloaded here.

In 2012 the HSE removed the 300 litre limit for hot and cold water systems so that all premises now fall within the scope of the ACOP.

What should a landlord do to comply with the ACOP?

A landlord must carry out a risk assessment to identify and assess potential sources of exposure and introduce a course of action to prevent or control any risk identified.

Assessing the risk

It should be possible for a landlord to assess the risk. However, if the landlord does not feel they have the right skills, they can obtain help and advice from a consultant.

A risk assessment should include consideration of the following:

• Are conditions right for the bacteria to multiply, e.g. is the water temperature between 20C and 45C?
• Are there areas where stagnant water occurs (deadlegs), e.g. pipes to a washing machine that is no longer used?
• Are there infrequently used outlets, e.g. showers, taps?
• Are there thermostatic mixing valves that set a favourable outlet temperature for legionella growth?
• Are any of your employees, residents, visitors etc vulnerable to infection, e.g. older people, those already ill?

Answering ‘yes’ to any of these questions suggests there is an increased risk of residents being exposed to legionella and falling ill.

Review the assessment periodically. The HSE suggest every two years or on change of tenant.

What should you do if you identify risks?

Introduce proper controls, which could include disinfection of the system – referring to the ACOP for guidance on the action to be taken.
As the design, maintenance and operation of the system are crucial in controlling the growth of legionella, any action you take is likely to include the following:
● ensuring water cannot stagnate anywhere in the system, e.g. remove redundant pipe work, run taps/showers in unoccupied rooms;
● keeping water cisterns covered, insulated, clean and free of debris;
● insulating pipe work
● maintaining the correct temperature at the calorifier (i.e. the hot water cylinder);
● advising tenants about the risks, the control measures you are taking and the precautions they can take, such as flushing through showers following a period of non-use. We provide advice to tenants both on our website and in their Information Folder.

Legionella are bacteria that are common in natural (rivers and lakes etc) and artificial water systems, eg hot and cold water systems (storage tanks, pipework, taps and showers). We usually associate legionella with larger water systems, eg in factories, hotels, hospitals and museums, and cooling towers, but they can also live in smaller water supply systems used inhomes and other residential accommodation. Other potential sources of legionella include spa and whirlpool baths, humidifiers (in factories) and fire-fighting systems (sprinklers and hose reels). Legionella can survive in low temperatures, but thrive at temperatures between 20oC and 45oC. High temperatures of 60C and over will kill them. Legionnaires’ disease is a potentially fatal form of pneumonia caused by the legionella bacteria. It can affect anybody, but some people are at higher risk including those over 45, smokers and heavy drinkers, those suffering from chronic respiratory or kidney disease, and people whose immune system is impaired. Legionellosis is the collective name given to the pneumonia-like illnesses caused by legionella bacteria, including the most serious and well-known Legionnaires’ disease, and also the similar but less serious conditions of Pontiac fever and Lochgoilhead fever.

Note: This information is provided as a guide only. Before relying on the material in any important matter, users should carefully evaluate its accuracy, currency, completeness and relevance for their purposes, and should obtain any appropriate professional advice relevant to their particular circumstances.